Regionalization of low flow for chosen catchments of the upper Vistula river basin using non-hierarchical cluster analysis

Abstract

The aim of this work was the regionalization of low flow for chosen catchments located in the upper Vistula river basin using non-hierarchical cluster analysis. Next, with such creative clusters, the regional relationships were determined between the specific low flow discharge q95 and the meteorological and physiographic parameters of the catchment. The study evaluated regional regression models for low flow (specific q95 discharge) in selected, 30 catchments located in the upper Vistula river basin. The data for calculations were a series of observations of daily discharge from the multiannual period of 1963–2016 and were obtained from the Institute of Meteorology and Water Management – National Research Institute in Warsaw. The study showed, that the k-means method can be used for regional regression determination. The parameters which influenced the catchments grouping in clusters were the specific low flow discharge q95, precipitation, median catchment altitude, mean catchment slope, soil, and land use. The study indicated that k-means method may be an effective tool for evaluating low flow in rivers of the southern parts of Poland.